Research and development in genetic testing for cancer susceptibility genes has advanced rapidly in recent years, allowing healthy individuals, cancer patients, and their families to determine if they carry mutations which increase their risk of breast, ovarian, prostate, colon, and other cancers. Initial efforts have unfolded primarily in academic medical centers targeting families at high risk for cancer. there is currently no information available for assessing the prevalence of genetic testing for cancer susceptibility genes at the national level, or for evaluating the knowledge of and attitudes toward such testing among primary care physicians. The objectives of this survey are to determine the utilization of genetic tests by physicians at the national level; to ascertain physician knowledge of available genetic tests for specific cancer susceptibility genes, to examine physicians' general attitudes toward testing, and; to explore possible variation in utilization and knowledge/attitudes by medical specialty, type of practice, year of training completion, board status, urbanicity, and geographic region. The primary research question that this survey will address is what is the prevalence of use of genetic testing for cancer susceptibility among primary care physicians in the U.S.?